The present invention relates generally to laser eye surgery methods and systems. More specifically, the present invention relates to methods and systems for differentiating between left and right eye images.
Known laser eye procedures generally employ an ultraviolet or infrared laser to remove a microscopic layer of stromal tissue from the cornea of the eye to alter the refractive characteristics of the eye. The laser removes a selected shape of the corneal tissue, often to correct refractive errors of the eye. Ultraviolet laser ablation results in photo-decomposition of the corneal tissue, but generally does not cause significant thermal damage to adjacent and underlying tissues of the eye. The irradiated molecules are broken into smaller volatile fragments photochemically, directly breaking the intermolecular bonds.
Laser ablation procedures can remove the targeted stroma of the cornea to change the cornea's contour for varying purposes, such as for correcting myopia, hyperopia, astigmatism, and the like. Control over the distribution of ablation energy across the cornea may be provided by a variety of systems and methods, including the use of ablatable masks, fixed and moveable apertures, controlled scanning systems, eye movement tracking mechanisms, and the like. In known systems, the laser beam often comprises a series of discrete pulses of laser light energy, with the total shape and amount of tissue removed being determined by the shape, size, location, and/or number of a pattern of laser energy pulses impinging on the cornea. A variety of algorithms may be used to calculate the pattern of laser pulses used to reshape the cornea so as to correct a refractive error of the eye. Known systems make use of a variety of forms of lasers and/or laser energy to effect the correction, including infrared lasers, ultraviolet lasers, femtosecond lasers, wavelength multiplied solid-state lasers, and the like. Alternative vision correction techniques make use of radial incisions in the cornea, intraocular lenses, removable corneal support structures, thermal shaping, and the like.
Known corneal correction treatment methods have generally been successful in correcting standard vision errors, such as myopia, hyperopia, astigmatism, and the like. By customizing an ablation pattern based on wavefront measurements, it may be possible to correct minor aberrations to reliably and repeatedly provide visual acuity greater than 20/20. Methods and systems for providing wavefront measurements continue to benefit from improvements and advancements, such as those described in U.S. patent application Ser. Nos. 10/300,714 and 10/460,060 (incorporated above by reference). Of course, wavefront measurement systems alone cannot eliminate all potential error from a laser eye surgery procedure. Errors may occur, for example, in transferring information from the measurement system to the ablation system or in the operation of the ablation system. One possible error that may be made is that a wavefront measurement image of a left eye may be confused with a wavefront image of a right eye. This may occur due to a mislabeling of the images, misinterpretation of the images by an operator of the ablation system, or the like. In a worst case scenario, wavefront measurement data for left and right eyes may accidentally be reversed, so that the treatment for the left eye is performed on the right eye and vice versa.
Therefore, it would be desirable to provide methods and systems for differentiating between left and right eye images. Ideally, such methods and systems would differentiate left and right eye images acquired using wavefront imaging technology and would reduce the likelihood of human error in a laser eye surgery procedure.